4:55 PM PT -- Mariah Carey will actually make a record $18 MILLION for her first year on "American Idol" -- more than J.Lo made before her ... and more than Britney on "X Factor."
It's official ... Mariah Carey has joined "American Idol."
The announcement was made moments ago at the TV Critics Association Summer Press tour in Beverly Hills.
The 42-year-old singer is rumored to have signed a deal worth $12 million for her first year ... the same amount of $$$ Jennifer Lopez made during her first year with the show.
'Idol' still has one more spot to fill at the judge's table ... and there are rumors Miley Cyrus and Adam Lambert could be in the running.